Value versus volume in the catch of the Spanish South-Atlantic Trawl Fishery

Abstract

An understanding of the link between the level of inputs and resultant level of outputs is of considerable importance when trying to manage fisheries through input controls. To this end, studies of several fisheries have been undertaken to examine this relationship through the estimation of production functions and frontiers, using either catch weight or revenue as the dependent variable. The choice of the appropriate output variable to use in the analysis will depend on the objectives of the fishermen. Maximisation of catch weight is often proposed as an objective of fishermen rather than maximisation of profits. In this paper, the technical efficiency scores of vessels operating in the Spanish south-Atlantic trawl fishery are estimated using the stochastic production frontier approach. The production frontiers are estimated with both the weight and the value of the catch as the dependent variable. The results of the analysis suggest that fishermen adopt a range of strategies but relatively few aim to maximise catch weight only. The differences in strategies may reflect heterogeneous attitudes towards risk, with more risk averse fishermen aiming to trade-off some potential catch value for a more certain quantity of catch.